Currier s knife



E. 13.- BRYANT. GURBIERS KNIFE.

Patented Jan. 13,1891.

FFE- Z- WWNESEEE- bmw/ UNITED STATES,

PATENT OFFICE.

HERBERT BERKLEY BRYANT, OF MANCHESTER, NEW HAMPSHIRE.

CURRIERS KNIFE.

SPECIFICATION forming part of Letters Patent No. 444,724, dated January 13, 1891.

Application filed September 13 1890. Serial No. 364,905. (No model.)

To @ZZ whom t may concern:

Be it known that I, HERBERT BERKLEY BRY- ANT, of Manchester, in t-he county of Hillsborough, in the State of New Hampshire, a citizen of the United States, haveinvented a new and useful Improvement in Curriers Knives, of which the following is a specification, reference being had to the accompanying drawings, forming a part thereof, in sufficiently full, complete, and accurate terms to enable a person skilled in the art to make and use my invention.

In the drawings, Figure l is a side elevation of a curriers knife of my improved Construction. Figs. 2 and 3 form abroken longitudinal section of the same on the line .e z of Fig. l on a larger scale, Fig. 2 of which is divided into two parts in the center of the handleTin order to make the drawing more compact endwise, and Fig. 2 is separated from Fig. 3 by a break which would represent the central portion of the knife shown in Fig. l. Fig. aisa transverse sect-ion of the knife upon the line y y of Fig. 1. Fig. 5 is a transverse section upon the line @c c: of Fig. l, Fig. 6 is anelevation of `the cross-handle, taken from the knife side of the handle; and Fig. 7 illustrates a section of the'ordinary curriers knife now in use at a point which corresponds to the section-line 0c c3 of Fig. l.

Curriers knives as now made are composed of six general elements or parts. These elements are the cross-handle at one end, the longitudinal handle at the other end, the straps which extend from one handle to the other and are provided with tangs or eXtensionsfwhich enter the handles and fasten the straps to the handles, and the two blades which are nipped between the straps and which serve to do the work. The transverse section in these straps in the knives as at marked B. The screw which unites the straps together and nips the blades between them is marked c a. It will be noticed that this screw is perpendicular to the dat surface p b and perpendicular to the plane of the blades. I have changed the shape of the transverse section of these straps and the position of the bindingscrew therein. The reason for changing the shape of the strap is this: It is necessary to grind the edges of the blades B with a long bevel on one side and a short bevel on the other in order that a wire edge may be formed upon the edge of the Scrapers to more readily take hold of the work. As however, it is necessary to grind these edges of the blades B from time to time, i-t has been found that the strap is apt to be ground with the edge of the blade on the side on which the long bevel is made, also when by use the blades have become narrow in the'old style of knife it is impossible to grind a thin edge on them, and they become useless, and that this injures the strap, and in oase the head of the screw which unites the strap together is not a countersunk head injures the screw-head. l have therefore made the transverse section of the straps at the place where they engage the blade in the form of a scalene triangle, of which one side corresponds to one of the sides p a of Fig. 7 and the other side corresponds with a line drawn from the upper termination of the line p a to the outer termination of the next adjacent side p a beyond the ilattened surface p b, and therefore have obliterated one of the apices or artes which lies between the iiattened surface p b and the inclined surface p a. This is shown very clearly in Figs. 4 and 5, which represent the transverse sections taken on the lines a; cc and y y of Fig. l. In this Way the two straps A and A of Figs. et and 5 present two opposite parallel surfaces s, which are ot' about twothirds of the width of the strap,

and two opposite parallel surfaces p, which are of about one-third of the width of the strap measured horizontally or on the line of the plane of the blades. ln constructing the straps of this transverse section the position of the screw which fastens them together is somewhat altered. A reference to Fig. 5 shows that the screw c, uniting the straps, binds them together on a line perpendicular IOO to the faces s, which line is inclined to the line of the screw in the old-fashioned curriers knife, (shown in Fig. 7,) as the axis of the screw c of Fig. is inclined to the dotted line w in that figure. It will be obvious that this change allows the long bevel ot' the blades B to be ground Without danger of touching the straps to the stone much more readily than with the old form. Iu addition to this, in the old form of knives the tangs at either end of the straps which fastened them to the handles had an internal angle at their junction with the body of the straps, as shown in the illustration of curriers knives found on page 424 of Dam'ss M anujttcture of Leather, published by Henry Carey Baird dt Co., Philadelphia,

1885, andthe sectional form ot' the tang of the straps was usually, it' not always, square.

, manner.

of the:knife'is to haveV the straps longV enough. to cover4 the edges of t-he -blades andto lcurve them into the tang gradually,' so as :to .form a smooth seat for the iingers of the operator, so that the" operators hand shallv be in no danger of callus orinj ury. This is shown clearly in Fig. 1. Thelstraps at their cross-handle. end are formed into taperingv tangs, as shown in Fig. 3, which terminate in screw-threadson their exterior at theA outer end. .These tangs are made, as shown in Fig.` 6, at the point where -they enter lthe handlev square,.thus `having a partial shoulder toward the blades. These tapering tangs are lettered f in Figs.r3 and 6. The cross-handle is lettered O. A tapering bore is lnade in it to conform to the shape of the tang, and at the outer. endot this bore a recess is made for the insertion of the nut g, which is driven upon the tangs by aspanner in the usualway. On the inner side of the cross-handle O another recess is made for the insertion of the bushing V, which bushing has, as shown in Fig. 6, a square,l hole in its center for the reception of the tangs,and'is heldin place on the'handle bymeans of two screws r, which are driven into the handle and engage with notches on the exterior of the bushing V, and thus prevent it from rotating, and also prevent theI cross-handle() from turning. upon the tang. Of course the bushing V may be held in its place in any other suitable and wellsknown The employment of screws engaging with `notches is a simple contrivance, and one :which anyfordinary mechanic could well execute; The long,` tang at the opposite end of the straps from the cross-handle is marked in the drawings d. It is usually made rounding, and` between it and the strap proper is a shoulder, (marked h in Fig. 2.) Thestraight handle T has a metallic ferrule N lupon its end adjacent to the strap, and this ferrule-is so formed that its'outer surface shall grad -ually form a smooth and rounded hollow for the fingers ot' the operator to clasp if he so desire, and the strap between the ferrule end and the blades is also rounded and smoothed and has a hollow bearing on the side next the blade, so that the fingers shall not be injured upon that side. The outer ends of the tangs d have a screw-thread cnt upon them, and the nut e draws them tightly in and holds them firm. This nut is count-ersunk into the end of the handle T and is set up with a Spanner. In order to hold these straps together and nip them upon the blades, I do not depend entirely uponl the bind to kbe got by the more or less tapering form of the tangs where they enter the handle, but I draw the straps together, as shown by screws c. vOnly two of these screws are representedfin the drawings;

but it is obvious that several maybe employed,

depend very much-upon the stiffness. ofthev metal of which the straps are'composed. In order to more readily loosenY the holdgof the straps upon the knives, set-screws a'are driven r into the blades adjacent to the'screws c, andv `these set-screws may either be driven into a for the reception of the endof theset-screw a.

The smooth rounding hollow` between the' bladesvB and the cross-handle O above referred to is marked la, andthe smoothiround- IOO I prefer, however, as the surest'the. Lmaking of a small recess, as shownm Fig. 4,

ing hollow between the handle" T and-the blades B is markedZ in Fig. l. These'hollows are. illustrated as far as-they can bein Figs. 2 and 3 as designated-"by the same letters;

I claim as "my invention' and. desire to se-Y' cure by Letters Patenty l. In curriers knives, thecombination of the bladesB and strapsA A', each 4having one exterior long surface s adjacent to one of the blades and one exterior short surface p adjacent to the'other of the blades',andeach blade having adjacent to it theexterior longv vsurface s of onestrap and the exterior short straps and compressing themupon the blades i perpendicularly to the long surfaces's of the:

straps and at an linclination with the blades,

substantiallyas described.

3. In curriers knives, the combination of the straps A A', each having one exterior long surface s and one exterior short surface j?, with each other, and with the blades B, and with the assemblingscrews c, and with. the set-screws d, substantially as and for the purpose described.

4c. In curriers knives, the combination of the blades B and straps A A', each provided with tangs, with the handle T and ferrule N, formed with a concave holdingsurface presented toward the edge of the blades I3, substantially as and for the purposes described.

5. In eurriers knives, the combination of the blades B and straps A A, each provided with a tang f, with the handle O, having a bushing` V recessed into the center of one I5 

